<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

  <style>

    #d1{
      width: 200px;
      height: 200px;
      border: 10px solid red;

      border-radius: 10px;
    }

    #d2{
      width: 100px;
      height: 100px;
      border: 1px solid red;

      padding-left: 50px;
      padding-top: 50px;

      box-sizing: border-box;
    }

  </style>
</head>
<body>
<div id="d2">内边距</div>
<div id="d1">边框测试</div>
</body>
</html>